1921445 has 4 divisors (see below), whose sum is σ = 2305740. Its totient is φ = 1537152.

The previous prime is 1921427. The next prime is 1921457. The reversal of 1921445 is 5441291.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1378276 + 543169 = 1174^2 + 737^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1921445 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 192140 + ... + 192149.

It is an arithmetic number, because the mean of its divisors is an integer number (576435).

2^1921445 is an apocalyptic number.

It is an amenable number.

1921445 is a deficient number, since it is larger than the sum of its proper divisors (384295).

1921445 is an equidigital number, since it uses as much as digits as its factorization.

1921445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 384294.

The product of its digits is 1440, while the sum is 26.

The square root of 1921445 is about 1386.1619674482. The cubic root of 1921445 is about 124.3204726344.

The spelling of 1921445 in words is "one million, nine hundred twenty-one thousand, four hundred forty-five".